If it were me, with thecal sac compression at those levels, I would be seeking the opinion of an experienced orthopedic surgeon, as well as another neurosurgeon. Naturopathy and chiropractics have their place in medicine and I do believe they can be beneficial. But with an MRI like that, I would definitely be looking to get the pressure off the cord and the neural foramina and get rid of the lower limb issues. Be on the look-out for symptoms of Cauda-Equina Syndrome (CES), which include loss of bowel and bladder control.
If you haven't already, check out
http://www.chirogeek.com and read up. Dr. Doug Gillard is a chiropractor who is also a lumbar spinal sufferer and has taken the time to make a "soup to nuts" tutorial of all things lumbar spinal in a plain language format.
Theresa